A vehicle hit a power box near a 50km/h speed sign, taking out power to the Rakaia township about 1.10pm last Tuesday.
The sign also appeared to be damaged. Due to this crash, emergency services reduced the road to one lane.
A nose-to-tail between three cars then happened in the lane, south of Rakaia, at 1.56pm on the same day.
St John said ambulances were sent to both crash scenes.
One patient was transported to Ashburton Hospital with minor injuries after the first crash, while two patients, one in a moderate condition and the other with minor injuries, were taken to Christchurch Hospital after the second.
Rakaia Volunteer Fire Brigade chief Tyrone Burrowes said despite the second crash, the cars were able to be moved so traffic continued to flow.
Firefighters at the scene assisted with traffic and treating patients until St John arrived.
Burrowes also owns the town’s Mobil garage. Losing power meant the garage’s fuel pumps went out of action and eftpos went down.
Power to most of the town was restored by 2pm and fully by about 5.30pm.
